D-Link DFL-1100 User Manual page 127

To accomplish this we need to create the following firewall settings:
Configure two static routes (one for each public IP we wish to forward)
-
- Create two port mappings (one for each public IP mapping to each private Server)
Routing configuration:
Static Route Configuration for a Server on the LAN:
Navigate to the SYSTEM tab, then the ROUTING page of the Web-based configuration.
Select the Add New link to create the first static route.
Select the Interface that the Internal Server is connected to (LAN or DMZ).
Specify the Public IP to be forwarded in the Network field.
The Subnet Mask should be set to 255.255.255.255 (1-host).
Enable the Proxy ARP feature.
The above static route configuration explicitly defines the interface that the additional
Public IP address should be forwarded to.